Uniform Resource Locator (URL) or a website address is a standard internet resource address. A general form of URL can be: <URL accessing method>://<host computer>:<port>/<path>, for example, https://mail.qq.com/cgi-bin/loginpage, which provides a webpage for login of QQ emails.
A whole URL often contains a large amount of characters. It is less convenient to use and spread the whole URL, especially in an environment requiring limited word counts. For example, microblog requires a limited word count of 140 words or less. Citing the whole URL may occupy a great length. Short URL services are desired and have been promoted.
The short URL service is also called short website address service. Conventional long URLs having large amount of characters may be converted into short URLs with less amount of characters according to a pre-set algorithm. For example, a long URL for accessing QQ email box can be https://mail.qq.com/cgi-bin/loginpage, which is converted by a short URL service to provide a short URL: http://url.cn/2GmfZ3. Thus, when the user inputs a conventional long URL into QQ microblog, corresponding short URL with less character can be displayed on the microblog. The short URL occupies less word count and is suitable for use in an environment with limited word counts.
Currently, when using a short URL service to convert a long URL into a short URL, the converted short URL can only correspond to the original long URL. Once the original long URL has been changed for any possible reasons, the short URL is useless and cannot be used to refer back to information related to the original long URL. Resources are thus wasted.